audio noob here. Please be gentle.
I'm required to design a box with a jack for a headset and connector for an unknown cable going to a Windows desktop PC.
Headset has the standard 3.5mm plug for microphone, r speaker, l speaker, and ground.
Intention is there's a user at desktop PC who will communicate with user of the headset.
Questions:
1) the box is only pass-through. what's the best cable I can use to pass these low-level signals between headset and Windows desktop PC? distance is 10-15 meters.
2) at desktop PC side, what's the best hardware I can use so Windows desktop PC can receive/process these signals? I'm thinking USB link to PC but not sure what's available out there.
TIA!
Related
I'm not sure if this is feasible, but here's the idea. I want my Linux PC to connect to the cell phone as if it's a headset, and then have the headset connect to the PC, as if the PC is a phone. Then look for a way to bridge or passthrough the audio, while using something like alsamixer to tap into the audio and save it to disk.
I have a bluetooth headset. When connecting it to Windows 10, it installs two profiles in Playback devices list:
Hands-Free. (HSP profile)
Stereo. (A2DP profile)
The Second one (Stereo) is set to be the "Default Device" and the "Default Communication Device" on the system.
When I start any program that uses the mic (recorder, chat, VoIP Calls, gaming, etc.) The sound suddenly stops working And I can only use the mic until I stop the recorder or the call.
To enable the sound again I need to make the Hands-Free (HSP) profile handle both input and output (sound and mic). Unfortunately, HSP gives really poor sound quality.
I want to know If there is a way, using code, I can change Bluetooth behavior so the two profiles work simultaneously. One handles the sound and one handles the mic so I can have high quality sound and use the mic at the same time.
You will probably never find a solution. I had the same problem (I was trying to create a walkie talkie with 2 headsets connected to the same smartphone).
On Windows (but also on Android) you can't access directly to a BT-microphone or BT-speaker because it is automatically detected as BT headset and the OS take the control of the device.
Your app can then access the OS-device and not directly the hardware device. The only OS able to do that was Symbian I think which had the most BT-protocols. On Windows you will probably never be able to do that and on Android you have to write your own A2DP-protocol if you want to access the device directly without OS interference.
So sad...
Luckily, under windows you can define different devices for communications and sound.
So, you have two choices:
Choosing Hands-free for both mic/speaker only for communication (which will switch back to A2DP after the call/teams).
Choosing another mic for communication which allow you to still use the speaker profile even in communication.
That is a bluetooth restriction : A2DP (high quality audio) cannot be use simultaneously with HFP (hands-free profile)
I know Microsoft doesn't allow the streaming of music from phones to Windows 8 PC's or the use of the PC as hands free, but has anyone found a way around this yet?
Are there any modified drivers or ways to modify the current drivers?
Any help would be appreciated.
www.bluesoleil.com offer a custom bluetooth driver that will make your pc show up as a Bluetooth headset to other devices. It will also allow you to choose which audio device the audio is repeated repeat to.
Product is not free but is the only solution is managed to find after half an afternoon looking. Works great as well.
I have built a home surveillance and alarm system with raspberry pi's.
What I need now is an easy and safe remote control to arm the system and disarm it.
The most workable solution is to have a wireless router in the middle.
Before stepping out in the door, take out my phone, connect to my home network and via a custom built web page arm my system. (Web page would run the arming scripts)
But for this I need to have a wireless router (currently I have a non wireless Ubiquiti Router Station Pro, no radio card on it) and need to enable wireless on my phone (it is not enable-d, battery reasons) before leave, connect and so on. It is not one click unfortunately...
Other solution is to have just a wireless dongle in the Raspberry PI and do an Ad Hoc WiFi connection with my phone. My phone is Sony Ericson Xperia. Over here my technical knowledge hits the limit. It is possible to broadcast an Ad Hoc network over Raspberry PI I do not know if I can reach it from my Sony Ericson Xperia phone.
Third option is Bluetooth. I know very little about Bluetooth. I do not know how safe it is, and how to program it, to have on and off switch on my phone. However this might be the most promising.
Fourth option is to use the Pi Face. Link one or two switches to some type of receiver device. Have a sender device on my key chain and control it from there.
However I do not know from where I can buy such a safe remote control and if it is compatible with Pi Face.
Fifth option. To get home alarm system components and link those with the Pi Face. But I do not know what component might fit.
The best user scenario is the following.
User takes out out a device (phone or remote control) and presses arm/disarm.
User has appropriate time (30 sec) to get out or shut down.
If the remote device had run out from battery still have something to shut it down.
So my question does any body knows a fast, easy, cheap solution how to do this?
Though Bluetooth's security is questionable, it seems like the best option for your goal. Next to an adhoc
Bluetooth is not complicated.
On your mobile phone, if you don't want to make your own app you can look for some sort of Bluetooth Terminal or Bluetooth Chat. On your raspberry pi you'll have to setup a bluetooth rfcomm server with bluez.
How to configure Linux to act as a Bluetooth RFCOMM SPP server?
RFCOMM without pairing using PyBluez on Debian?
Modify these servers which do nothing by default, to listen for commends "arm" and "disarm". Make sure the ID of the device is the ID of your phone.
Ad-Hoc is even less complicated (assuming you know how to make a webserver and are going to make it secure enough, and have a dongle which supports adhoc):
Here is a post about ad-hoc networking with a raspberry pi.
In terms of distance, you'll have to see the specifications on your dongle(s) but I would say they're relatively the same.. your bluetooth dongle will have a class see Bluetooth Basics: Range. This will require more research but if you have either one of the dongles I would use that method.
I hope this helps, good luck setting up your alarm.
In the mean time I realized that a fast arming could be done via the Pi Face and pressing a button.
Disarming could go by other ways.
However the fastest solution would be a fingerprint button linked safely to Pi Face.
Updates. Finally went with the Ad-Hoc method:
This is the tutorial for it:
http://elinux.org/RPI-Wireless-Hotspot
Is there a way to use one computer to send keystrokes to another by usb ?
What i'm looking to do is to capture the usb signal used by a keyboard (with USBTrace for example) and use it with PC-1 to send it to PC-2.
So that PC-2 reconize it as a regular keyboard input.
Some leads to do this would be very appreciated.
What you essentially need is a USB port on PC-1 that will act as a USB device for PC-2.
That is not possible for the vast majority of PC systems because USB is an asymmetric bus, with a host/device (or master/slave, if you wish) architecture. USB controllers (and their ports) on most PCs can only work in host mode and cannot simulate a device.
That is the reason that you cannot network computers through USB without a special cable with specialised electronics.
The only exception is if you somehow have a PC that supports the USB On-The-Go standard that allows for a USB port to act in both host and device mode. USB-OTG devices do exist, but they are usually embedded devices (smartphones etc). I don't know if there is a way to add a USB-OTG port to a commodity PC.
EDIT:
If you do not need a keyboard before the OS on PC-2 boots, you might be able to use a pair of USB Bluetooth dongles - one on each PC. You'd have to use specialised software on PC-1, but it is definitely possible - I've already seen a possible implementation on Linux, and I am reasonably certain that there must be one for Windows. You will also need Bluetooth HID drivers on PC-2, if they are not already installed.
On a different note, have you considered a purely software/network solution such as TightVNC?
There is a solution:
https://github.com/Flowm/etherkey
This uses a network connection from your computer to the raspi which is connected to a teensy (usb developer board) to send the key strokes.
This solution is not an out-of-the-box product. The required skill is similar to programming some other devices like arduino. But it's a complete and working setup.
The cheapest options are commercial microcontrollers (eg arduino platform, pic, etc) or ready built usb keyboard controllers (eg i-pac, arcade controllers,etc)
SEARCH THIS PROGRAM:
TWedge: Keyboard Wedge Software (RS232, Serial, TCP, Bluetooth)
then, MAKE YOUR OWN CONNECTION CABLE WITH:
(usb <-> rs232) + (NULL MODEM) + (rs232 <-> usb)
Connect 2 computer, write your own program to send signal to your (usb <-> rs232) unit, then you can control another computer under the help of TWedge.
The above mentionned https://github.com/Flowm/etherkey is one way. The keyboard is emulated from an rPi, but the principle can be used from PC to PC (or Mac to Whatever). The core answer to your question is to use an OTG-capable chip, and then you control this chip via a USB-serial adapter.
https://euer.krebsco.de/a-software-kvm-switch.html
uses a very similar method, using an Arduino instead of the Teensy.
The generic answer is: you need an OTG capable, or slave capable device: Arduino, Teensy, Pi 0 (either from Rapberry or Orange brands, both work; only the ZERO models are OTG capable), or, an rPi-A with heavy customisation (since it does not include USB hub, it can theoretically be converted into a slave; never found any public tutorial to do it), or any smartphone (Samsung, Nokia, HTC, Oukitel ... most smartphones are OTG capable). If you go for a Pi or a phone, then, you want to dig around USB Gadget. Cheaper solutions (Arduino/Teensy) need custom firmware.